Steam automobile motor appliances
It was not until 1889 that steam traction on roads resumed a new phase in the direction of vehicles for pleasure. In the decade previous to this date the English road laws and the opposition of turnpike companies appear to have almost extinguished road steam locomotion in England. It was to have a new birth in France, under more liberal road laws and regulations.
In M. Serpollet was developed the spirit of evolution for the horseless carriage, which in his hands made rapid strides. With the development of the explosive and electric motor industry, the spirit of progress became epidemic in France and rapidly spread throughout the Continent, England and the United States.
M. Serpollet's boiler was a marked innovation towards lightening the source of power, and the flash boiler seemed to take on a useful form, although the principle had been tried before and failed to meet the requirements. In Fig. 18 is represented one of the steam tricycles of M. Serpollet.
His first boiler did not have the fuel magazine, and is shown in vertical section, Fig. 19, and in horizontal section in Fig. 20.
The flash coil generator, Fig. 21, at first made of 1 1/2 inch lap-welded iron pipe, flattened and coiled as in Fig. 21, and afterward of steel or copper pipe, corrugated, as shown in the cut. The elongated aperture within the coil was about
1/8 of an inch wide. It was placed above the fire, as shown at A, Fig. 19. They were tested at i,500 pounds per square inch to insure safety at any probable pressure, a working pressure
of 300 pounds being the practical limit. For a larger generator two coils, one above the other, were placed over the furnace and their ends connected so that the water injection was first through the lower coil.
In this method of generating steam there is no valves between the boiler and engine; the injection pump works constantly while the vehicle is running, and the amount of water fed to the boiler is regulated by a three-way cock operated by a convenient handle for directing the required amount of water to the boiler, the excess returning to the tank through the third port in the cock. The feed pump could also be started by hand for the first charge. For stopping the motor, the water was shut off from the boiler.
Incrustation was not found in this type of generator with ordinary clean water; the high velocity of the water and steam through the narrow spaces was found to sweep any sediment clean from the surface and to discharge it through the cylinders and exhaust.
The evaporated power of one coil was reported to be equal to 40 pounds of water, or more than one boiler horse power, with a grate surface of i08 square inches.
This looks somewhat surprising, yet a record of i5 miles per hour with two persons on the tricycle was frequently made. The Serpollet boilers were further increased in power for larger vehicles by changing the form of the tubes, as shown in Figs. 22 and 23, and nesting them in series, as shown in Fig. 24, and stacking, as in Figs. 25 and 26.
The furnace, Fig. 25, shows a longitudinal section, and Fig. 26 a cross section, showing the fire door and the cold air inlets above the fire, operated by a sliding damper for admitting cold air over the fire when the vehicle is standing. This being the plan of boiler used in the larger vehicles, had a furnace composed of fire brick tiles, set in a framework of special channel and tee forms of iron to hold the tiles securely, and the whole was encased in a sheet-iron box lined with asbestos.
Further improvements were made by substituting gasoline or kerosene burners, one of which is shown in Fig. 28, in which the inlet at J received the oil under a low pressure by compressing the air in the oil tank sufficiently for overcoming the friction in the burner coil and maintain a vapor
pressure at the jet for a full fire and governed by a cock in the oil pipe for reducing the flow of oil and the intensity of the fire. The oil entering at J, passes into the coil, S, becomes vaporized and passes down through the end of the coil, j, into the base, B, and up through the central burner tube, C, through the slotted nozzle, O. A plug at b, and the screw closure at the top of the burner nozzle, can be removed for the purpose of cleaning the burners. The air passes up through the arms of the base, B, as shown in the
side diagram, and mingles with the vapor at the base of the coil. A small cup placed below the burner, charged with alcohol, served to heat the burner and lower part of the coil sufficient for starting the burner with oil.
An improved and larger burner by M. Languemare is illustrated in Fig. 29, which has a central valve to control the vapor flow close to the burner tips—a very good arrangement, as the oil or gasoline that may be in the fluid state in the lower part of the coil may be checked from feeding the burners more readily than by a valve in the feed tube, A. The valve wheel, D. is operated by ratchet wheels and chain connection with the seat.
The cut represents a five-tip burner. The four tips, FF, in the arms of the frame are adjusted by screwing up or down for any desired size of aperture. The central tip is also adjusted by a screw, but is hollow, with side holes, to
allow the vapor to pass to the outer tips. The cup, E, is for starting the burner with alcohol. Other forms of these burners are in use. Those for gasoline require much less coil surface for vaporizing and are made in helical nests of three or five, with straight sides or cylindrical casings.
In Fig. 30 is shown an English submerged vertical tube boiler with interior circulating deflectors; a liberal steam and water level surface and well adapted for coal, coke or gasoline burner.
De Dion and Bouton, in France, made several models of boilers for vehicles, one of which, Fig. 3i, is a vertical boiler with an outside water space connected to an inside water cylinder by inclined tubes, with a diaphragm across the inner cylindrical shell between the two upper rows of tubes for producing dry steam by circulating the steam generated in each compartment through the upper tubes.
This boiler is especially applicable for coal or for a gasoline torch furnace, which can be fixed to the grate lugs. Another form of boiler, made by the De Dion-Bouton
Co.. is of the magazine type, derived from Fig. 3i, in principle , but with an annular central shell and down draft smoke pipe, illustrated in Fig. 32.
This boiler, it will be seen, has every other vertical section of tubes closed at their outer end and expanded in the outer sheet of the inside section of the boiler, while the alternate tube sections are expanded in both sections of the boiler.
The magazine, C, is closed by an air-tight cover, AT, and the draft regulated by the sector cover, O. The end joining of the two pair of cylindrical shells, it will be observed, are made by annular grooved plates held by through bolts, in the author's opinion, a not very reliable construction for a high pressure boiler.
The boiler of the steam fire engine, made by the Gould Manufacturing Co., Seneca Falls, N. Y., Fig. 33, is a type of the vertical tube system with a water fire box and submerged tubes. Its conical smoke chamber and central smoke pipe gives this type of boiler many advantages in having the water line above the tubes and a large steam space so desirable for this class of boilers.
It is the general type of boiler used in England for traction engines, trucks, road rollers and other heavy steam' vehicles. In the United States the horizontal or locomotive form of boiler is largely in use for road rollers and traction engines.
Boilers and burners
In Fig. 34 is illustrated a boiler made by the Clarkson & Capel Co., London, and used with the burner, Fig. 35, on their four-ton dray. The tubes in this type are only inclined from the horizontal enough to make a free circulation. The conical fire box
has a large heating surface and receives the first impact of the flame. In Fig. 35 is illustrated the Clarkson & Capel burner. The oil enters the vaporizing coil at the bottom turn at E, as shown by the dotted line; is vaporized by the flame of the burner and the vapor carried through a continuation of the coil to the needle valve chamber at J. The spindle of the needle valve, N, is pivoted to the arm of a rock shaft that extends to the outside of the mixing chamber, T, and connects by the arm, L, and the lever, L', to the burner spindle and valve for regulating the flame at E. A cross bar at B guides the spindle, which
is threaded on its upper end to allow the valve to be adjusted so as to close at the same time that the vapor needle valve at / closes. The valves are operated by a lever on the rock shaft and a link extending to a convenient place for the driver to handle.
At A is a rotary valve for regulating the inflow of air for diluting the oil vapor as it passes along the tube, T. A hand torch is used to heat the vaporizing coil before the oil is allowed to enter.
In Fig. 36 is illustrated a very effective boiler, with a central chamber made from eight or ten-inch lap welded iron pipe, with both heads drawn in and welded solid, as is done with the compressed air bottles or they maybe riveted and calked, as with other boilers.
The fingers may be made of 3/4-inch iron pipe, from 4 to 5 inches long, welded up and squared or flattened on the welded end to receive a box wrench. The other ends to have the standard pipe thread.
The casings may be made of No. i2 sheet iron, covered with asbestos and enclosed in a thin sheet iron case. The fuel evaporating coil may be made of f iron or copper pipe, and connected to a burner frame, as in Fig. 36 and Fig. 37. The boiler, Fig. 37, is made of steel boiler plate with water leg and internal finger tubes made in the same manner as above described. It may have an outside case of thin sheet iron with asbestos packing on the cylindrical part.
The boiler, Fig. 38, with a shell made of copper, No. i0 wire gauge, and heads of i-inch sheet steel, flanged and riveted to the shell, illustrates a good practice for small boilers.
The diameter for 4 horse power should be i5 inches by i5 inches in height. The heads should be laid out for 350 copper tubes ^-inch diameter, No. i4 wire gauge, cut to project £-inch beyond each head and expanded by a suitable Dudgeon expander and the ends flanged out.
The vaporizing tube, as used in the Stanley system, enters under the edge of the shell, extends up through one of the tubes and down through another tube to the burner case. With this arrangement, a separate air jet must be used to start the boiler, after which the heat of the boiler is sufficient to vaporize the gasoline in the pipes within the boiler tubes.
The jet burner, Fig. 39 is a hollow casting consisting of two rings with connecting necks, the upper surface having from 60 to 75 holes about fa of an inch diameter, through which the vapor meets the air drawing through the spaces within and around the rings.
The jet burner, Fig. 40, may be made with two disks of J-inch steel plate with the edges flanged over to shut tight with a ^-inch space and brazed, with a collar for connecting the vapor pipe. The holes for air feed may be laid out and drilled in one head before the heads are brazed, which makes the drilled head the template for drilling the other head.
The size of the holes must be made to exactly fit the selected size of the steel tubing from which to make the thimbles ti fill the holes and to be expanded and the edges flared to make a secure joint. The size of the thimbles may be 3/4 or 1 inch, and the number may be from i0 to 30, to suit the size of burner required. The jet holes should be j'j-inch in diameter and in number suited for the size of the boiler from three to five hundred. One thousand holes, 1/32 will only equal the area of 5/16-inch pipe.
Boilers and engines for steam motor vehicles
In Fig. 41 we illustrate a multiple vertical tube boiler made by Milne & Killam, Everett, Mass., who are now building boilers, burners, regulators and engines, with complete equipment for steam motor carriages.
The vehicle boiler here illustrated is the stock pattern supplied to vehicle manufacturers, weighs complete but i30 pounds. It is 15 inches in diameter and 15 inches high, arid will generate steam under normal pressure for 4 horse power. It is built with a steel shell and has 380 copper tubes, each 14 inches long, giving a heating surface of 56 square feet. The working pressure is 140 pounds, and each boiler is tested at 350 pounds. The boiler is covered with asbestos and aluminum. It is fitted with dry steam pipe, water glass fittings, gauge cocks and blow-off pipe, holes for water feed and steam gauge connected; also a multiple tube cylindrical burner i5 inches diameter, 5 inches deep> with automatic gasoline regulator.
The engine, Fig. 42, furnished with the boilers of this company are very compact and are models of concentrated energy. They develop on extreme call 6 horse power, although they develop but 4 horse power with the usual boiler pressure of i40 pounds per square inch.
It is of the four cylinder, single acting, reversible type and runs in oil in a draft-proof case; perfectly balanced and noiseless. Four cranks set at 90" from each other, gives a perfect balance, and do away with all vibration. What is meant in this engine by "single-acting" is, that steam is admitted to one end of the cylinders only, therefore, the pressure on the working parts is aways in one direction, which prevents any noise or pounding.
The engine is hung or suspended by the top, permitting it to swing fore and aft to allow for adjustment of the driving chain. This arrangement also does away with any fore and aft strain on the engine or rear axle that would occur if the engine was stationary while going over rough roads. The steam pipe is so arranged that no strain is brought upon it by fore and aft movement of the engine.
The new serpollet steam motor.
The new steam motor of Leon Serpollet is designed much on the same principles of the straight line double cylinder gasoline engines. It is illustrated in Fig. 43 in part sectional elevation, plan view, end view and a section of the compression sub-piston and inlet port at the lower right hand corner of the cut. It was designed for using the superheated steam generated in the flash boiler.
Steam is admitted by valves at the end of each cylinder, which are operated by cams on a secondary shaft geared to the crank shaft: The exhaust for each cylinder is by a port opened by the piston at the forward end of its stroke, as shown on the left hand cylinder in the elevation figure of the cut.
By this arrangement the steam is only exhausted during the moment of the end of the impulse stroke. The steam remaining in the cylinder is compressed on the return stroke in the whole space up to the inlet valve. The supplementary plunger piston moving in the neck of the inlet passage is longer than the piston stroke; it is hollow, with side ports at about half stroke.
The operation is, then, that the return stroke of the piston compresses the steam remaining in the cylinder and inlet pipe until one-half the return stroke is made, when the ports in the sub-piston close and the compression in the cylinder is rapidly increased, making a strong cushion of steam in
both the cylinder and inlet pipe. The inlet valve then opens, letting in a charge of high pressure and temperature steam; not against the full area of the large piston, but against the area of the sub-piston and following it until the small side ports open and the compression of the large piston is partly exhausted by expansion, when the inrush of the high pressure steam gives a powerful impulse during the middle of the crank stroke.
The amount of steam required for a vehicle engine should not be much greater than for other small engines of slide valve type. The variable cut-off from the reversing link motion, with the probable leakage in valves and piston, for a light runabout using an average of one and a half indicated horse power at a fair traveling speed of i0 miles per hour, should use no more than 35 pounds of water per horse power hour. For a 30-mile trip this would be 105 pounds or about 13 gallons, which will be a small storage capacity for such a vehicle, and may admit of a much larger storage, say for a 50 mile trip. The gasoline or oil storage for a 30mile trip should be 16 pounds, or say 3 gallons—or for a 50mile trip, 5 gallons. If a surface air draft condenser is used and mineral oil used to lubricate the cylinder the scaling of a boiler may be considerably delayed, and with a small portion of caustic soda or any alkali added to the tank water if lime be present in any of its combinations, will prevent its adhesion to the boiler shell or tubes and can be blown out from the boiler at high pressure entirely clean, following a few minutes after extinguishing the burner. Every vehicle boiler should be provided with the means of quickly blowing out the contents whenever necessary. A further guard against fouling of the boiler may be provided by an elevated tank in the vehicle stable to catch and filter rain water, or for treating hard water with a solution of triphosphate of soda, which will coagulate the lime and allow it to settle, when the pure soft water may be drawn for the boiler.